摘要： 傳統(tǒng)的多普勒流速剖面測(cè)量?jī)x將混頻正交與低通濾波在軟件中實(shí)現(xiàn),，存在測(cè)量時(shí)間長(zhǎng)、精度不高等問(wèn)題,。為解決上述問(wèn)題,，采用運(yùn)算速度更快、內(nèi)存容量更大的 STM32H743單片機(jī)作為主控芯片,，同時(shí)設(shè)計(jì)了將信號(hào)混頻,、正交與 FIR 低通濾波在硬件電路中實(shí)現(xiàn)的多普勒流速剖面儀，這樣大大減少了 CPU 的運(yùn)算時(shí)間,，提高了測(cè)量精度,。運(yùn)用 FFT 算法進(jìn)行信號(hào)質(zhì)量分析，利用自相關(guān)算法計(jì)算出各層流速,。通過(guò)試驗(yàn),，對(duì)測(cè)得的多普勒頻偏以及流速進(jìn)行分析，結(jié)果表明,，系統(tǒng)的設(shè)計(jì)滿足在實(shí)際小型河流中的精確測(cè)量,，具有可行性。
中圖分類號(hào)： TN913 文獻(xiàn)標(biāo)識(shí)碼： A DOI：10.16157/j.issn.0258-7998.200546 中文引用格式： 張羽,，李永倩,，鮑帥，等. 聲學(xué)多普勒流速快速測(cè)量的設(shè)計(jì)[J].電子技術(shù)應(yīng)用,，2021,，47(5)：54-58. 英文引用格式： Zhang Yu，Li Yongqian,，Bao Shuai,，et al. Design of rapid measurement of acoustic Doppler velocity[J]. Application of Electronic Technique，2021,，47(5)：54-58.
Design of rapid measurement of acoustic Doppler velocity
Zhang Yu,，Li Yongqian，Bao Shuai,，F(xiàn)an Hanbai
College of Electrical and Electronic Engineering,，North China Electric Power University，Baoding 071000,，China
Abstract： In traditional Doppler velocity measurement, mixing quadrature and low-pass filtering are generally implemented in software, which results in relatively long measurement time and low accuracy. In order to solve the above-mentioned, STM32H743 single chip computer with faster operation speed and larger memory capacity has been used as the main control chip, and a Doppler velocity profiler is designed by using signal mixing, orthogonal and FIR low-pass filtering in the hardware circuit, which greatly reduces the CPU operation time and improves the measurement efficiency. At the same time, FFT algorithm has been used to analyze the signal quality, and autocorrelation algorithm has been used to calculate the velocity of each layer. Through the experiment, the frequency deviation and velocity are analyzed. The results show that the design of the system can meet the requirements of accurate measurement in actual small streams, and it is feasible.
Key words : orthogonal mixing,；Doppler velocity profiler；quality analysis,；autocorrelation algorithm
0 引言
傳統(tǒng)的聲學(xué)多普勒流速剖面儀(Acoustic Doppler Current Profiler,，ADCP)在單片機(jī)內(nèi)部進(jìn)行正交變換、FIR濾波來(lái)獲取多普勒頻偏信號(hào)的實(shí)部和虛部,，最后通過(guò)自相關(guān)算法計(jì)算出多普勒頻偏,，得出流速,，由于正交變換和FIR濾波等均在軟件中完成，因此數(shù)據(jù)處理的時(shí)間較長(zhǎng),，并且硬件電路需要外擴(kuò)SRAM,，不便于電路設(shè)計(jì)，成本也較高[1],。本系統(tǒng)采用內(nèi)存1 MB,、主頻高達(dá)400 MHz的STM32H743作為CPU，無(wú)需外部SRAM[2],，并將回波信號(hào)的正交變換以及FIR低通濾波在硬件電路中實(shí)現(xiàn),，通過(guò)單片機(jī)內(nèi)部16 bit的A/D轉(zhuǎn)換器，同時(shí)對(duì)兩路正交信號(hào)進(jìn)行采樣,，這樣數(shù)據(jù)處理的速度顯著提高,，測(cè)量的精度也進(jìn)一步提高，在實(shí)際工程中具有很強(qiáng)的實(shí)用性,。
